They are often ­mistaken for sisters. And their babies, born just five days apart, are ­sometimes taken for twins.

But identikit blondes Kirsty Cox and Anna Jones are in fact a ­married couple, and three-month-old Scarlett Marie and Alfie are biologically half-brother and ­sister.

The babies were conceived just two weeks apart with the help of sperm donor Nick Lacey, who got both women pregnant on the first attempt through DIY ­artificial ­insemination.

Kirsty, 22, says: “We’ve got two beautiful babies and sometimes we have to pinch ourselves to ­believe it’s really ­happened.

“Anna and I had accepted we might not be able to have ­children. But now we’ve been blessed with a family, and it’s all thanks to Nick for making it happen. He’s given us the most amazing gift.”

Hairdresser Nick, 24, says: “As a gay man I thought I’d never have the chance to have a biological child myself, but now I’ve helped create two. People might think our situation is unusual... but the babies are lucky enough to have three parents who dote on them.”

Blonde on blonde: Kirsty Cox (left) and Anna Jones on their weddding day (Image: SM)

Kirsty and Anna’s journey to motherhood began soon aftertheir lavish civil ­ceremony in June 2010, when the lookalike brides, both from Gloucestershire, wore ­elaborate white gowns and matching tiaras.

“Anna and I always wanted kids, and after we got married our desire became even stronger,” says Kirsty. “Neither of us was prepared to sleep with a man, and IVF wasn’t an option either as it was too expensive.

“We could have applied to the NHS but that meant only one of us could have it, and we both really wanted to have the experience of giving birth.

“That’s when the topic of sperm ­donation came up. It meant we could both try to get pregnant and we hoped to use the same donor. We knew it might take a while to find the right person, but we were prepared to wait.”

In fact, they didn’t have to wait too long at all. A twist of fate brought Nick into their lives when, in November 2010, Anna’s sister Lorraine got chatting to her hairdresser about her sister’s ­burning desire for children.

Kirsty says: “Anna got a call from Lorraine saying she might have found us a donor. She said the guy wanted to meet us and see what we were like before making a decision.

“He wanted to know if we were in a stable relationship and to make sure it wasn’t just a phase we were going through. He sounded like the real deal.”

Nick says: “I didn’t feel ready for kids of my own but I’d thought about sperm donation. If I was going to be a donor I wanted to do it as a gift for people I knew would make great parents.

“When Lorraine mentioned that her sister and her wife were desperate for kids, something just clicked into place. I thought, ‘I can really help these girls’.”

So in love: The couple exchange vows (Image: SM)

Two days later, Nick and the girls met up for a chat. Kirsty says: “We were so nervous. We knew it was going to be like a job interview. We expected Nick to judge us. In fact, we wanted him to. The last thing we wanted was some guy who hadn’t really thought it through.

“When we met Nick we knew he was serious. He had loads of questions. We told him to think about it really carefully before making a decision.”

The three met up another couple of times before, in December 2010, two weeks after their first meeting, they got a call from Nick to say he would love to be their donor. Nick says: “As soon as I met Kirsty and Anna, I could tell they’d make ­fantastic mums.

“I didn’t want to be paid and it would all be on their terms. If they wanted me to see the baby, then great, and if they didn’t, then that was fine too. I just wanted to help.”

Kirsty and Anna, 27, arranged for Nick to have a comprehensive check-up, then last January, they made their first attempt at DIY artificial insemination, with Kirsty as the intended mother.

She says: “Anna and I were so ­nervous. Nick did what he had to do while we waited in the bedroom. After Anna inseminated me with a syringe, I kept saying to her, ‘There’s no way this is going to work!’ We hadn’t even planned it around our ovulation cycles.”

But the couple pressed on two weeks later, this time with Anna.

‘‘We agreed with Nick that he’d come once a week and we’d keep trying until one us got pregnant,” says Kirsty.

“To be honest, we expected it to take at least a year, if it happened at all.”

But just three weeks later, Kirsty thought she might be pregnant. Unable to believe it, she carried out EIGHT home ­pregnancy tests to make sure.

“We couldn’t believe it had happened so quickly,” she says. “We were ­screaming and hugging each other. The first thing we did was text Nick.”

They were even more shocked a couple of weeks later Anna started ­getting stomach cramps.

“I warned her she might be pregnant but I was only joking,” says Kirsty. “Then we realised she was. I remember we were both sat in the bathroom sobbing with happiness.”

Nick says: “When the girls told me the news, I was thrilled for them. They said they wanted me to be involved.”

Kirsty says: “We went through every step of our pregnancies together. We were thrilled when we found out Anna was expecting a boy, and the next day I learnt I was going to have a little girl.

“Because we look similar, people ­assumed we were sisters. They’d come up to us and say, ‘Oh how lovely that you’re pregnant at the same time’. I had to keep telling people that Anna was actually my wife. It was really funny.”

Last November 5, Kirsty gave birth to Scarlett-Marie, who was two weeks overdue. Five days later, Anna gave birth to Alfie. The girls are now ­enjoying full-time motherhood.

Kirsty says: “Nick saw the babies when they were a few days old, and he brought round a big bunch of flowers for us and some vests for the babies with the words, ‘I love my mummies’ across them. It was really sweet.

“The babies’ birth certificates have mine and Anna’s names on them as we don’t see Nick as their dad. We don’t want to confuse the kids. As far as we’re all concerned, they have two mummies and Nick was the donor who made it all happen. But we plan to be very honest with them when they grow up.

“Nick is certainly a big part of their life. It may not be a traditional family set-up but it works brilliantly for us.

“We’d love to have more kids one day, and be thrilled if Nick would be the donor. He’s given us the perfect family and we’ll always be grateful to him.”

Nick, who sees the children once a week, adds: “Although I don’t see myself as their dad, I adore the babies and I intend to be part of their lives forever.

“ I never imagined I’d have a child, and I never knew I’d have so much love for them.”